Residual antimalarials in malaria patients from Tanzania--implications on drug efficacy assessment and spread of parasite resistance.

Repeated antimalarial treatment for febrile episodes and self-treatment are common in malaria-endemic areas. The intake of antimalarials prior to participating in an in vivo study may alter treatment outcome and affect the interpretation of both efficacy and safety outcomes. We report the findings from baseline plasma sampling of malaria patients prior to inclusion into an in vivo study in Tanzania and discuss the implications of residual concentrations of antimalarials in this setting. In an in vivo study conducted in a rural area of Tanzania in 2008, baseline plasma samples from patients reporting no antimalarial intake within the last 28 days were screened for the presence of 14 antimalarials (parent drugs or metabolites) using liquid chromatography-tandem mass spectrometry. Among the 148 patients enrolled, 110 (74.3%) had at least one antimalarial in their plasma: 80 (54.1%) had lumefantrine above the lower limit of calibration (LLC = 4 ng/mL), 7 (4.7%) desbutyl-lumefantrine (4 ng/mL), 77 (52.0%) sulfadoxine (0.5 ng/mL), 15 (10.1%) pyrimethamine (0.5 ng/mL), 16 (10.8%) quinine (2.5 ng/mL) and none chloroquine (2.5 ng/mL). The proportion of patients with detectable antimalarial drug levels prior to enrollment into the study is worrying. Indeed artemether-lumefantrine was supposed to be available only at government health facilities. Although sulfadoxine-pyrimethamine is only recommended for intermittent preventive treatment in pregnancy (IPTp), it was still widely used in public and private health facilities and sold in drug shops. Self-reporting of previous drug intake is unreliable and thus screening for the presence of antimalarial drug levels should be considered in future in vivo studies to allow for accurate assessment of treatment outcome. Furthermore, persisting sub-therapeutic drug levels of antimalarials in a population could promote the spread of drug resistance. The knowledge on drug pressure in a given population is important to monitor standard treatment policy implementation.

Absence of residual Hodgkin's disease demonstrated by PET/CT in a deceased organ donor.

With the current limited availability of organs for transplantation, it is important to consider marginal donor candidates, including survivors of potentially curable malignancies such as lymphoma. The absence of refractory/recurrent residual disease at the time of brain death can be difficult to establish. Therefore, it is critical to have objective data to decide whether to proceed or not with organ procurement and transplantation. We report a unique situation in which (18)F-fluorodeoxyglucose positron emission tomography (PET) was used to rule out Hodgkin's lymphoma recurrence in a 33-year-old, heart-beating, brain-dead, potential donor with a past history of Hodgkin's disease and a persistent mediastinal mass. PET showed no significant uptake in the mass, allowing organ donation and transplantation to occur. We present a new means of evaluating potential brain-dead donors with a past history of some lymphoma, whereby PET may help transplant physicians by optimizing donation safety while rationalizing the inclusion of marginal donors.